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| Check If Someone Is Using Your WiFi |
There are many
reasons why you'd want to check if an unauthorized party is using your wireless
network. It may be that you're experiencing a slower than normal Internet
connection or you simply don't want anyone getting a free ride while you pay
the bill. Of course, there are also security implications if this person can
somehow access files on your network, and even legal implications if he uses
your connection for piracy or other illicit activities.
Whatever the case
it's better to stay on the safe side. Many of you may have already taken some
basic precautions when setting up your wireless network and know your way
around troubleshooting these issues. This brief guide is aimed mostly at novice
users in need a hand to find out if, indeed, their Wi-Fi is being stolen.
Check the devices associated with your router
The first thing you
need to do is login to your router's administrative console by typing its IP
address directly into the browser address bar -- typically 192.168.0.1 or
192.168.1.1 depending on which router you have. If you don't know your router's
default address check out this guide or simply go to the command prompt (Start
> Run/Search for cmd) and enter ipconfig. The address you need should be
next to Default Gateway under your Local Area Connection.
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| Picture of Command Prompt Showing Default Router Address |
NOTE: Here In the Image I don't have any routers to indicate If u have a Router It will display near the indication mark in the Image.
Alternatively, if you
are on a Mac, you can find the default address by going to Network under System
Preferences. It should be listed right next to "Router:" if you are
using Ethernet, or by clicking on "Advanced…" and heading to the
"TCP/IP" tab if you are using Wi-Fi. Next, point your browser to that
address and enter your login details -- if you haven't changed the default
settings it should be a combination of "admin" and
"password" or blank fields. Here's a default username and passwordlist (PDF) you might find useful, but we recommend you change this afterwards.
Once inside your
router's administrative console look for a section related to connected devices
or wireless status. In my old DIR-655 from D-Link it's available under Status
> Wireless but you'll find it as "Attached Devices" in Netgear
routers, under DHCP Clients Table on Linksys routers, "Device List"
if you are using the Tomato firmware, and so on.
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| Picture of DHCP Client Table showing list of connected devices |
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| DHCP client list examples on D-Link and Linksys routers. |
This should provide a
table with the IP, MAC address and other details of every device currently
connected to the router. Check that list against your gear to find any
intruders. You can find out the MAC/IP address of your computers by going to
the Command Prompt again and entering 'ipconfig /all'. The MAC address will be
shown as the physical address. I'll let you figure it out for mobile devices
like smartphones and media players since I can't possibly list all options.
Taking action
The best and simplest
solution is to set up a strong password using WPA2 or WPA -- WEP is very easy
to crack so avoid that if possible. There are some other methods you can use to
beef up security, like switching off the SSID broadcast (which prevents it from
advertising the name of your network to nearby Wi-Fi devices) or setup a filter
for allowed or blocked devices by MAC address. It won't stop the most
determined intruder but it will slow him down.
That should be more
than enough for most users but if you need to actually track down who's been
breaking into your network it's possible to pinpoint his physical location
using a tool called MoocherHunter. You'll need to burn a Live CD to boot your
laptop with and walk around to track down unauthorized wireless clients.
According to the program's description, it detects traffic sent across the
network and can find the source within 2 meters accuracy.
Needless to say,
we're not suggesting you take matters into your own hands, but it might come in
handy if someone is getting you in trouble with authorities using your network
for illegal purposes -- or simply to have a cool story to tell.
